How do I call Javascript from Clojurescript?

Question

I am currently learning clojure and I am trying to translate some javascript from CodeCombat to clojure/clojurescript.

var base = this;
var items = base.getItems();
if (base.built.length === 0)
    base.build('peasant');

I am trying to convert the Javascript code to Clojure, but unfortunately CodeCombat doesn't give me any error message.

(def base this)
(def items (.getItems (base) ))
(def built-len ((.length) (.built (base)) ))  
(if (= built-len 0)
    ((.build "peasant") (base) )))

Do you see any obvious mistake? I mostly followed the offical interop tutorial http://clojure.org/java_interop

There are many differences between Clojure and ClojureScript, so I suggest you focus on one. The ClojureScript documentation shows how to do JS interop. github.com/clojure/clojurescript/wiki/… — Jeremy
– Jeremy, Commented May 20, 2014 at 20:47
See this question on how to access this from ClojureScript stackoverflow.com/questions/15531261/… — Diego Basch
– Diego Basch, Commented May 20, 2014 at 21:33
Remember that putting parens around something tries to call the first item in the list as a function. Are you sure you want to call the string "peasant" as a function? — Chuck
– Chuck, Commented May 21, 2014 at 0:11
I am currently learning clojure and clojure script too. And maybe it would help you. This is how I do what you're talking about and it works for me (defn get-url [path] (.getURL js/chrome.extension path)) — Igor Tyulkanov
– Igor Tyulkanov, Commented May 21, 2014 at 4:56

user8472 · Accepted Answer · 2018-09-18 12:15:41Z

2

Use this-as macro ! However, using def is not nice inside macro... it's preferred to use let if possible!

(this-as t
  (let [item (.getItems t)]

In your code remove parenthesis around base, (it's function call, and you don't want to call it).

user8472

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answered May 21, 2014 at 8:59

markus

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